You think I'd know better - Trix 2-10-0 rebuild

[mmagliaro]

Well, I just destroyed one Trix motor trying to get the brass worm off the shaft.   Put so much force on it with the gear puller it bent the gear puller, snapped the plate, exploded the motor across the shop, magnets went flying.   Worm still firmly on shaft.  But I think I discovered the old Roco red plastic worms will work.

I've pulled brass worms off of Trix shafts before, never had this happen.   Calvinball.

Sorry about your motor!

I've found the Trix worms to be some of the most ungodly difficult ones to get off. I can never do it without
ruining/bending the ram on a small gear puller.  I got one off a B6 motor once by placing it under my milling machine head,
hung in a very thick steel plate with a notch cut in it.  Like the K4 motor, there is plenty of room between the worm and the front of the motor, so you can slip a really thick plate in there.  A steel octagon box (like you would mount in your ceiling for a light fixture) works great for this.   Just cut a slot in one of the sides and hang the motor in there.

I put a cut off shank of a wire drill as close to the size of the worm hole as I had (I save my broken wire drills to use as rams).  I let it stick out of the nose of the milling chuck only like 1/16", and then brought the head down as a ram to push the shaft out.

A drill press would work just as well, as long as the chuck closes enough to grip a tiny wire drill firmly.

[peteski]

DM-Toys sells a nice selection of brass worms for various diameter shafts.  They are inexpensive, but the shipping will be more costly (but still reasonable). They also sell coreless remotoring kits,  including for that ubiquitous Minitrix motor.
https://www.dm-toys.de/en/list/manufacturer/MicromotorEU.html

For a better list of available conversions see Micromotor's website.  It is in German, but it is easy to follow.
https://micromotor.eu/Motorising-Kits-Umbausaetze-Ombouwsets/N-gauge-Spur-N/Minitrix/

[mmagliaro]

That place is a great find, Pete!
Kit NM010G  (29.99 EUR, so about $32, plus the shipping from Europe)  is a drop-in coreless replacement
for the German prototype that looks like the same chassis as the minitrix decapod.  They are very clever.
They made different 3D printed motor "carriers" for a standard corless motor size, so that it could be dropped into
a ton of different chassis.  You just glue the motor into the carrier, put on the worm with Loctite, and the whole assembly
slides back in, in place of the original motor.  Easy peasy.  And no, I'm not a schill for the company, ha ha.

[randgust]

Meanwhile, back in reality.... 

The Kato motor mount is done, looks pretty good, did well in the cradle and after the Goo sets I'll wire and start testing under load.  But the low-RPM torque is pretty darn good.  Even with the workbench throttle, I could get it to crawl.   John's sand dome is on now too.   There's JUST enough cab to hide it.



link:  http://www.randgust.com/PRRL1008.jpg



link:  http://www.randgust.com/PRRL1009.jpg



link:  http://www.randgust.com/PRRL1010.jpg

[Lemosteam]

Meanwhile, back in reality.... 

The Kato motor mount is done, looks pretty good, did well in the cradle and after the Goo sets I'll wire and start testing under load.  But the low-RPM torque is pretty darn good.  Even with the workbench throttle, I could get it to crawl.   John's sand dome is on now too.   There's JUST enough cab to hide it.



link:  http://www.randgust.com/PRRL1008.jpg



link:  http://www.randgust.com/PRRL1009.jpg



link:  http://www.randgust.com/PRRL1010.jpg

Looks great Randy.,

[randgust]

Although you might not see it, there's an insulator strip between the bottom brush holder and the frame.   I'm still not sure if I'm doing this DCC or not, I have to get it to run right first, but the wheels are insulated from the frame, and the motor is insulated from the frame, so it's possible.

I want to redesign the plug system to the tender to be a little more flexible, particularly if this ends up being a 4-wire hitch instead of 2.

John, I'm kinda hoping that by the time I get this thing to run right you'll solve the pilot deck and air tank problem for me!

You also can't see it but there's a big lead slug pounded into the front of the boiler ahead of the original cast weight.   I also reprofiled the steam dome to plug the screw hole.   I've reduced the plastic boiler to an undetailed shell, I'm following Max's article on detailing it and I have pretty much all the parts.   Brass running boards are done but not attached.

Note that I had to tip the motor just a hair to make the ex-Roco worm engage fully.  I think the rear-end shim was .010.   And it's very counter-intuitive to glue the motor to the frame, but I've done this with these on 6 locomotives before and it's worked just fine.   Those Kato motors are just incredible for performance.

[mike_lawyer]

Although you might not see it, there's an insulator strip between the bottom brush holder and the frame.   I'm still not sure if I'm doing this DCC or not, I have to get it to run right first, but the wheels are insulated from the frame, and the motor is insulated from the frame, so it's possible.

I want to redesign the plug system to the tender to be a little more flexible, particularly if this ends up being a 4-wire hitch instead of 2.

John, I'm kinda hoping that by the time I get this thing to run right you'll solve the pilot deck and air tank problem for me!

You also can't see it but there's a big lead slug pounded into the front of the boiler ahead of the original cast weight.   I also reprofiled the steam dome to plug the screw hole.   I've reduced the plastic boiler to an undetailed shell, I'm following Max's article on detailing it and I have pretty much all the parts.   Brass running boards are done but not attached.

Note that I had to tip the motor just a hair to make the ex-Roco worm engage fully.  I think the rear-end shim was .010.   And it's very counter-intuitive to glue the motor to the frame, but I've done this with these on 6 locomotives before and it's worked just fine.   Those Kato motors are just incredible for performance.

Which Kato motor are you using?  Is it the one from the Mikado or another one?

[randgust]

I bought a batch of these back in the 70's to experiment with - as far as I know they were the original motors to the Con-Cor PA1, which was just a beast.   I bought 7 of them; four of them were used to repower my Model Power RSD15's (and they are still going) and three of them went to Atlas / Roco GP9 repowerings for a friend, and when he passed, I got them back.    This is one of those motors.    Unobtanium, but they sure like the very same dimensions as the LL motor, just not skewed poles.

I also have another one that ended up in my Trix F7 as an experiment, I think that was a Mashima instead of a Kato, but same deal, and it's equally a five-pole beast.

They are wide for most hood units, I had to dremel out the shells to make them fit, but it was worth it.   Astounds me how they can sit there and grind on full slip and never heat up.   Trix or Roco or Yugo motors would erupt in flames.

[nickelplate759]

...   Trix or Roco or Yugo motors would erupt in flames.

Not sure if that was meant as a joke or not, but I actually did have a Roco motor (in an Atlas/Roco E7) go up in smoke, during an N-Trak show.  Pretty dramatic, not to mention hard on the shell.   

[randgust]

You have to go back to 1972, but I bought a new Atlas GP40 in Santa Fe (Roco) at the Whistle Shop Hobby Shop in Pasadena.

Believe it or not, the instructions actually said to lubricate it with vegetable oil, which I did.   Which got sticky, so you just put more in it..... Hey, I was 15.

And with the sticky overload, the little motor got quite hot.   Fire rings, then that caught the vegetable oil on fire inside the shell.   What was neat about those GP40's was the open radiator fan holes, so the smoke poured out of those like a turbo fire.   There was enough oil coating the inside of the shell it melted a hole through in the shell, too, before I could blow it out.   Trashed.   But I still kept the shell with the hole burned in it, have chunks of it today.    What us old-timers (now) put up with....    If it hadn't been for my used Trix F7 I would have given up N scale.

[peteski]

Yes, those motors were terrible. Very weak magnets and tiny armature with very thin wire windings.  Funny thing it that it was a 5-pole motro, and the commutator was also nice (actually machined, not one of those formed copper contacts like Rivarossi used).  With the high-friction mechanisms of the day, they used to work hard and get really hot.

The Model Power FA I donated to Lee had one of those motors. I upgraded the motor by replacing the weak magnets with small rare-earth magnets, It gave it a bit more pep, but it was still nowhere as food as any contemporary motor.

[nkalanaga]

Randgust:  For many years I ran my bedroom layout with Trix F7s.  The BN had plenty of them, so it wasn't out of line, but four units are excessive for switching!  I could have gotten by with two, but four looked better.

Wired together, all-wheel pickup meant that stalls were very rare, even with a smoky wood stove in the house.

[wm3798]

...The Model Power FA I donated to Lee had one of those motors. I upgraded the motor by replacing the weak magnets with small rare-earth magnets, It gave it a bit more pep, but it was still nowhere as food as any contemporary motor.

I'm sad to report that it still melted down, wrecking the under frame.  The shell is still decent, but it's been relegated to the parts bin.  The newer Life Like FA2, even the older lead sled version, is far superior, so there's little point in effecting a further repair.
Lee

[randgust]

When you go back to that era, most motors really were awful.    The Trix motor in the F-unit had soft brushes and created fire rings.  So did the U-boats, not quite as bad, but you still had to regularly clean commutators and put in brushes.   You'd get a really good motor in the Trix units, and some were excellent, but as the dies wore the quality went way down. 

The Rivarossi can motors would overheat, shift the bearing in the plastic end cap, and you're done.  And the soft magnets attracted 'stuff', jamming them.   Tiny armatures by comparison. The only armature I ever successfully rewound and repaired was a Rivarossi after a burn-out in a coil.

The Roco motors were a complete POS, never saw a good one, either the original ones or the ones in the Atlas GP9/F units.

Rapido motors were rugged, but impossible to maintain if the brushes got contaminated or fire rings.  I cut holes in the black plastic just to clean the commutators, but I never burned one out.

So the only motors of the era that really, really set the standard were the Kato PA1's.    Still some of the best, never lost one.

Today, it's really unusual to have a bad motor that either toasts or requires regular maintenance.   We take it for granted, and even the micro ones with finger brushes are relatively robust.   I can't remember the last time I either toasted a motor or had to tear one apart just to clean it, or even replace brushes.    The last motor to croak I had was probably 12 years ago, one of the Tomytec TM originals.   I've had Atlas motors that were just plain noisy, but usually that has more to do with flywheels being out of balance than the motor design.    And I've had Kato motors develop the 'screech' but one drop of oil has fixed that for years.

[peteski]

I'm sad to report that it still melted down, wrecking the under frame.  The shell is still decent, but it's been relegated to the parts bin.  The newer Life Like FA2, even the older lead sled version, is far superior, so there's little point in effecting a further repair.
Lee

Oh well . . .
I know you were big on keeping the models in their original condition, so I tried to make the original motor a bit stronger.  No love lost - I was going to toss that model anyway.  Actually, this was a good (even if failed) experiment.